Atrial fibrillation risk loci interact to modulate Ca2+-dependent atrial rhythm homeostasis.
J Clin Invest
; 129(11): 4937-4950, 2019 11 01.
Article
em En
| MEDLINE
| ID: mdl-31609246
ABSTRACT
Atrial fibrillation (AF), defined by disorganized atrial cardiac rhythm, is the most prevalent cardiac arrhythmia worldwide. Recent genetic studies have highlighted a major heritable component and identified numerous loci associated with AF risk, including the cardiogenic transcription factor genes TBX5, GATA4, and NKX2-5. We report that Tbx5 and Gata4 interact with opposite signs for atrial rhythm controls compared with cardiac development. Using mouse genetics, we found that AF pathophysiology caused by Tbx5 haploinsufficiency, including atrial arrhythmia susceptibility, prolonged action potential duration, and ectopic cardiomyocyte depolarizations, were all rescued by Gata4 haploinsufficiency. In contrast, Nkx2-5 haploinsufficiency showed no combinatorial effect. The molecular basis of the TBX5/GATA4 interaction included normalization of intra-cardiomyocyte calcium flux and expression of calcium channel genes Atp2a2 and Ryr2. Furthermore, GATA4 and TBX5 showed antagonistic interactions on an Ryr2 enhancer. Atrial rhythm instability caused by Tbx5 haploinsufficiency was rescued by a decreased dose of phospholamban, a sarco/endoplasmic reticulum Ca2+-ATPase inhibitor, consistent with a role for decreased sarcoplasmic reticulum calcium flux in Tbx5-dependent AF susceptibility. This work defines a link between Tbx5 dose, sarcoplasmic reticulum calcium flux, and AF propensity. The unexpected interactions between Tbx5 and Gata4 in atrial rhythm control suggest that evaluating specific interactions between genetic risk loci will be necessary for ascertaining personalized risk from genetic association data.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fibrilação Atrial
/
Retículo Sarcoplasmático
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Fatores de Transcrição
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Cálcio
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Sinalização do Cálcio
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Loci Gênicos
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Homeostase
Tipo de estudo:
Etiology_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article